Scientists looked at factors that could impact the drought, including temperature, rainfall, humidity, wind speed and other factors and found that climate change intensified the drought in California between 8% and 27% in the period from 2012 to 2014.

Park Williams, a climate scientist at Columbia University and the lead author of the paper, said he hoped the findings would motivate the state to continue thinking about its response to the drought with a long-term strategy.

“California, I believe, has a history of when droughts end, they have a history of discontinuing their efforts to improve resiliency to future drought because those efforts are costly in the short-term,” Williams said.

But this strategy is not sustainable, according to the study. “I hope that the measures that are under way now to improve resilience to droughts don’t end as soon as it gets wet again in a few years,” Williams said.

His comments are particularly prescient as California prepares for rain from the El Niño weather phenomenon – which the National Weather Service said could be one of the strongest to ever hit the state. The storm system is known for bringing heavy rains to California, though it is not expected to have a significant impact on the drought.

The report predicts that if the current drought continues, it will most acutely harm low-income rural communities and California’s forests and wetlands, putting the region’s biodiversity under “extreme threat”.

The National Oceanic and Atmospheric Administration announced on Thursday that July was the hottest month in history since record-keeping began in 1880. This came a month after scientists announced that the first half of 2015 was the hottest recorded.